According to the FBI, you're looking at Sabu, the head of LulzSec, and the de facto King of Anonymous—easily the most notorious and influential hacker alive today. One thing: he just turned in his people to the police.

The name Sabu should be familiar: as part of LulzSec, a potent offshoot of Anonymous, he masterminded legendary attacks against the CIA, FBI, Sony, and numerous other corporate and government targets. He was their Captain Hook. That was before. Fox News reports the shadowy hack deity is not only confirmed to be unemployed 28-year-old New Yorker Hector Xavier Monsegur, but that Sabu has been "collaborating with the government for months," leading to a string of arrests around the world today. It's unclear how many will be dragged down with Sabu's nine months of federal collaborating, but it's safe to assume whatever vestiges of LulzSec remained are toast—we'll know for sure when all of the indictments are unsealed.

And according to Fox, the dragnet was thick:

On August 15, 2011 Monsegur pleaded guilty to more than ten charges relating to his hacking activity. In the following few weeks, he worked almost daily out of FBI offices, helping the feds identify and ultimately take down the other high-level members of LulzSec and Anonymous, sources said.

That's right—the man who helped the internet celebrate #FuckFBIFridays was doing so from an FBI desk. But only after the feds wielded Sabu's children against him:

"He didn't go easy," a law enforcement official involved in flipping Sabu told FoxNews.com. "It was because of his kids. He didn't want to go away to prison and leave them. That's how we got him."

I've talked to Sabu multiple times, and on each occasion he's seemed more and more distant, to the point where it was hard to get in touch with him at all. Now, says the FBI, it's because he was busy ratting out his cadre.

This also isn't the first time Sabu's been accused as a snitch—a prominent hacker and Sabu-detractor by the name of Virus I spoke with last year ranted about his hunch that the LulzSec leader was a rat:

6:12:32 PM virus: I don't have proof of him being a snitch, and he doesn't have proof of me being a snitch. it's my word against his.
6:15:39 PM virus: he disappeared for a week, I don't recall what day
6:15:52 PM virus: but when he returned he said his grand mother died and that's why he was MIA
6:16:01 PM virus: after that he started offering me money to own people
6:16:14 PM Sam Biddle: anyone important?
6:16:55 PM virus: backtrace security and laurelai
6:17:22 PM virus: he gave me IPs, asked me to access their accounts with their IP and asked me to access their emails
6:17:25 PM virus: told me he would pay me
6:17:42 PM Sam Biddle: did you?
6:17:53 PM virus: no, I found that to be suspicious and declined

...

6:19:19 PM virus: another reason why I believe he was converted after he disappeared and returned is everybody else started getting arrested one by one starting with ryan clearly, who was their ddos bitch
6:19:29 PM virus: yes, I believe he cut a deal to save himself

This August conversation jibes perfectly with Fox's report, who says Sabu began working for the FBI in June after they busted him—it's unclear what his fate is now. What is clear is the enormous grin of the feds, who have finally fired one back after almost a year of humiliations and runarounds from Anonymous brass:

"This is devastating to the organization," said an FBI official involved with the investigation. "We're chopping off the head of LulzSec."

Though LulzSec proper has been dormant since last summer, Sabu has remained a hugely influential character atop a vast cult of personality. The revelation that he's sold out the movement he professed to love so much will deal as much a psychological as logistical blow to Anon. After all, the guy tweeted this, only yesterday:

"The federal government is run by a bunch of fucking cowards. Don't give in to these people. Fight back. Stay strong."